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</o:shapelayout></xml><![endif]--></head><body bgcolor=white lang=EN-IE link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-family:"Book Antiqua",serif;color:#943634;mso-fareast-language:EN-US'>And C++ also requires that some parts of the interfaces from C are presented to C++ as functions - examples being ‘</span><span style='font-family:"Courier New",serif;mso-fareast-language:EN-US'>fpclassify</span><span style='font-family:"Book Antiqua",serif;color:#943634;mso-fareast-language:EN-US'>’, ‘</span><span style='font-family:"Courier New",serif;mso-fareast-language:EN-US'>signbit</span><span style='font-family:"Book Antiqua",serif;color:#943634;mso-fareast-language:EN-US'>’ etc. These have to be handled differently, and I think that the current LibC++ approach to these is good and maintains semantic compatibility with C.<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Book Antiqua",serif;color:#943634;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-family:"Book Antiqua",serif;color:#943634;mso-fareast-language:EN-US'>I had intended to build a patch file of my changes today in case anyone is interested, but other things got me busy. I’ll do that tomorrow and attach it to this thread.<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Book Antiqua",serif;color:#943634;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-family:"Book Antiqua",serif;color:#943634;mso-fareast-language:EN-US'>I think that it is a good idea to have LibC++ provide its own wrapper headers for the C headers. It is a logical place to deal with portability issues that arise when referring to C headers provided by </span><span style='font-family:"Courier New",serif;mso-fareast-language:EN-US'>newlib</span><span style='font-family:"Book Antiqua",serif;color:#943634;mso-fareast-language:EN-US'>, </span><span style='font-family:"Courier New",serif;mso-fareast-language:EN-US'>uclibc</span><span style='font-family:"Book Antiqua",serif;mso-fareast-language:EN-US'> </span><span style='font-family:"Book Antiqua",serif;color:#943634;mso-fareast-language:EN-US'>or </span><span style='font-family:"Courier New",serif;mso-fareast-language:EN-US'>glibc</span><span style='font-family:"Book Antiqua",serif;mso-fareast-language:EN-US'> </span><span style='font-family:"Book Antiqua",serif;color:#943634;mso-fareast-language:EN-US'>(and other less well known implementations). The handling of these portability issues will mean that the ‘</span><span style='font-family:"Courier New",serif;mso-fareast-language:EN-US'>c</span><span style='font-family:"Book Antiqua",serif;color:#943634;mso-fareast-language:EN-US'>’ prefixed C++ headers will need little or no alteration and just maintain the ‘</span><span style='font-family:"Courier New",serif;mso-fareast-language:EN-US'>std</span><span style='font-family:"Book Antiqua",serif;color:#943634;mso-fareast-language:EN-US'>’ namespace.<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Book Antiqua",serif;color:#943634;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-family:"Book Antiqua",serif;color:#943634;mso-fareast-language:EN-US'> MartinO<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Book Antiqua",serif;color:#943634;mso-fareast-language:EN-US'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext'>From:</span></b><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext'> cfe-dev [<a href="mailto:cfe-dev-bounces@lists.llvm.org">mailto:cfe-dev-bounces@lists.llvm.org</a>] <b>On Behalf Of </b>Craig, Ben via cfe-dev<br><b>Sent:</b> 26 January 2016 19:42<br><b>To:</b> <a href="mailto:cfe-dev@lists.llvm.org">cfe-dev@lists.llvm.org</a><br><b>Subject:</b> Re: [cfe-dev] LibC++ v3.8 - Problems with ISO C wrapper headers<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal style='margin-bottom:12.0pt'>With regards to "where do we want to be", we shouldn't take the complete opposite approach and have the libcxx provide none of the C headers. At a minimum, we need a libcxx version of tgmath.h that hides the C version of tgmath.h. The generic macros from tgmath.h would play havoc with the overloaded functions in cmath.<br><br>Maybe all the other libcxx C headers could forward to the underlying C headers (or maybe not), but tgmath.h (and maybe others I'm forgetting) are special, and should not forward to the underlying C header.<o:p></o:p></p><div><p class=MsoNormal>On 1/25/2016 4:30 PM, Marshall Clow via cfe-dev wrote:<o:p></o:p></p></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><div><div><div><p class=MsoNormal>On Sat, Jan 23, 2016 at 12:46 PM, Howard Hinnant <<a href="mailto:howard.hinnant@gmail.com">howard.hinnant@gmail.com</a>> wrote:<o:p></o:p></p><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-top:5.0pt;margin-right:0cm;margin-bottom:5.0pt'><p class=MsoNormal style='margin-bottom:12.0pt'>[snip]<br>Martin is 100% correct as far as historical intent goes. The mis-interpretation of these words by Richard and Eric is evidence that the standard remains buggy in this area.<o:p></o:p></p></blockquote><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>While I bow to Howard's experience and to his recollection, I have to disagree with his characterization of Richard and Eric's posts as "mis-interpretation".<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>I believe that they have accurately reflected what is written in the standard.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>But that's just a nit.<o:p></o:p></p></div><div><p class=MsoNormal>The real questions are - where do we want to be, and how can we get there?<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>(and let's not forget <a href="http://cplusplus.github.io/LWG/lwg-defects.html#2086">http://cplusplus.github.io/LWG/lwg-defects.html#2086</a>) as well, which implies that there is no support for user-defined types in <cmath>.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>-- Marhsall<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div></div></div></div><p class=MsoNormal style='margin-bottom:12.0pt'><br><br><o:p></o:p></p><pre>_______________________________________________<o:p></o:p></pre><pre>cfe-dev mailing list<o:p></o:p></pre><pre><a href="mailto:cfe-dev@lists.llvm.org">cfe-dev@lists.llvm.org</a><o:p></o:p></pre><pre><a href="http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev">http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev</a><o:p></o:p></pre></blockquote><p class=MsoNormal style='margin-bottom:12.0pt'><o:p> </o:p></p><pre>-- <o:p></o:p></pre><pre>Employee of Qualcomm Innovation Center, Inc.<o:p></o:p></pre><pre>Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project<o:p></o:p></pre></div></body></html>